CC is immortal. Probably she is already 250 years old
Horo is a deity. Who knows what is her age?
Lia. Hmm... She revealed her age near the last episode. I think it's over 1000 already. I forgot.
Ciel and Arcuid. Ciel is immortal until she killed the person he is looking for (who is that guy? I forgot). Arcuid is a vampire who lived for thousands of years already.
Sakura. Even after the time skip of Da capo (70 years?), she has not grown up at all.

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Is Miku even an anime character?

first , the image I just put it there it have nothing to do with the topic .

and when I said old I meant to the time that the anima go on the air .

Then at least know that we are talking about anime oldies (in character), not anime oldies (in date released).